Method of dehydrating nitrocellulose and the product thereof



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Patented Mar. 14, 1933 r ARTHUR LANGMEIER, OF DOVER, NEW JERSEY, PANY, 0F WILMINGTON, DELAWARE, A

METHOD or DEHYDRATING mmocmwmss AN THE rRODUC fTHERnoE My invention relates to a novel method stored for long periods and safely shipped over long distances and under unfavorable conditions, as in ocean shipments.

It is well known that nitrocellulose, in the process of its manufacture, is subjected to washings with water in order to remove the nitrating acids, and that while excess water may be readily removed from the nitrocellulose mechanically, as by pressing or centrifuging, a certain amount of water tenaciously clings to it and can only be effectively removed by other than mechanical means. The water not readily removed from nitrocellulose by mechanical means has heretofore been removed by the use'of alcohol, as, for example, ethyl alcohol, which when percolated through" a mass of nitrocellulose, from which the excess of water has been removed, acts to displace the residual water.

It is well known that nitrocellulose when in a dry condition is highly inflammable and is not only unsafe to work, but its storage or shipment, when dry, is prohibitively dangerous; at the same time it is equally well known that if the nitrocellulose is in .a wet condition, that is, if the fibres be wetted with a liquid, that it is relatively non-inflammable and may be safely worked, stored, or shipped.

Now I have discovered that if nitrocellulose carrying water, be washed with amyl alcohol, removal of the water, or dehydration, will be effected and if an amount of theamyl alcohol suflici ent to wet the fibres of the nitrocellulose be permitted to remain in the nitrocellulose after dehydration is complete, its inflammability will be so reduced as to permit it to be stored, or shipped, over long periods and under highly unfavorable conditions.

As an illustrationof the carrying out of Application filed May 2 4,

' of the nitrocellulose to a long periods.

that is to say damp,

ess IeNoR ro ametes rown' Zita fem ooRPoRA'rIoN or ne awAR 1927.": "seriai nm aasaa 1 the process embodying my invention, nitrocellulose which has been washed,and which 7 carries a relatively large-amount of water,

is subjected to mechanical treatment to effeetremoval of= excess water. the nitrocellulose may be After the removal of the excess For example,

centrifuged. water, amyl alcohol, which may be commercial-amyl alcohol, approximating v,95%,- is per'colated through the mass until the residual water is I removed. The fected in a centrifuge, othersuitable apparatus. When the-residu al "water is eliminated from the nitrocellulose, the excess of amyl alcohol is removed by mechanical. means, as, forexample, by centrifuging or pressing, the'alcohol content being reduced to say within the range 20% 40% or, for example, to about 30%. When the excessof amyl alcohol has been removed, the nitrocellulose, .t-he fibres of which or shipment. have discovered, is of that it is an excellent ready for use, storage The amyl alcohol, I peculiar advantage in dehydrating medium and to reduce the infiammability, or fire hazard marked extent at the same time the amyl alcohol willremain with the nitrocellulose high temperatures, thus insuring the consubsequently acts even under relatively percolation may be.'ef-- in a press,-0r"1n any are 1 thoroughly wetted with amyl alcohol, is

tinuance of the wetted condition thereof for out disadvantage into practically all compositions of which nitrocellulose is an ingredient and in manycompositions its presence is advantageous.

Having. now fully described my invention,

ters Patentis c 1. The method of treating nitrocellulose, which comprises passing amyl alcohol through a mass of damp nitrocellulose for the removal of water therefrom and removing the'exces's of said alcohol from the mass by mechanical means.

2. The method of treating nitrocellulose, which comprises centrifuging a mass of Wet nitrocellulose to remove excess water, percolating amyl alcohol through the damp The amyl alcohol enters with- 7 what I claim and desire to protect by Letmass for the displacement of residual water and finally centrifuging the mass to remove the excess of said alcohol.

3. The method of treating nitrocellulose, 5 which comprises removing excess water from a mass of wet nitrocellulose, percolating an excess'of amyl alcohol through the damp mass for the displacement of residual water, and reducingthe alcohol content of the mass to withinthe range from about 20% to 40% by mechanical means. 4. Nitrocellulose, the fibres of which are wetted with amyl alcohol. 5. Nitrocellulose containing from about to 40% of amyl alcohol substantially uniformly distributed throughout the mass. 6. The method of treating nitrocellulose, which comprises centrifuging a mass of wet nitrocellulose to remove excess water, per- 20 colating amyl alcohol through the damp mass for the displacement of residual water and finally pressing the mass to remove the excess of said alcohol.

7 Nitrocellulose wet with amyl alcohol, the product being substantially dehydrated. 8. Nitrocellulose wet with about amyl alcohol, the nitrocellulose being substantially dehydrated.

In testimony of which invention, I have 30 hereunto set my hand, at Wilmington, Del.,

on this 19th day of May, 1927.

ARTHUR LANGMEIER. 

